i'm not sure if you meant glitch like hatching a Pokemon through a glitch or that the mon itself is a glitch, but I assume you meant the last one.
heres the list for gen IV (platinum):
well, I can't guarantee any of them being safe, but don't try the bad egg. ------ is the only one you can perform without a cheating device
gen V (white 2)
you can only see these with a cheating device
i know nothing about glitch pokés, so please don't ask touch about these. you can search for these glitches as bulbapedia is lacking a bit info about them.
here is a list of some other glitches:
again, iknow nothing about glitches, so please just google it rather than asking me as I know absolute nothing.
hope I helped :D